A two-sided ring-spinning machine with a bobbin-changing apparatus for simultaneously changing full bobbins for empty ones on both sides of the machine has a pair of gripper beams each moved by a respective push/pull member via a respective scissor linkage to grab the full and empty bobbins on each side of the machine.
In order to be able to move this gripper beam in and out and up and down as is necessary for changing the bobbins, each beam is held on a scissor linkage which is pivoted about a shaft in the lower region of the spinning machine or is mounted in a traveling slide. The drive for up-and-down movement of the gripper beam is effected by longitudinal movement of the shaft as described in European patent publication 445 375 of W. Klaus or a pull rod mounted in the slide as described in German 20 45 263 or by pulling members as described in German 17 85 217 on the scissor linkage. Electric motors and shaft drives as described in European patent publication 445 374 or fluid-powered drive elements as described in above-mentioned German 20 45 263 are used to power the push/pull element.
Even when, as is the rule, it is necessary to change full bobbins with empty ones on both sides of a two-sided spinning machine and the gripper beams are moved synchronously along the two sides of the machine, a separate element (spindle drive, piston/cylinder unit) producing the push or pull movement is provided for each of the gripper beams as described in German 21 58 657. The ring-spinning machines of the applicant are delivered with the drives of the two drive shafts powered by a single electric motor, but have for each machine side a separate push-or pull-producing element in the form of a threaded spindle with a nut.